Optical disc with high disc scanning speed, and related apparatus and method for using such optical disc

ABSTRACT

A laser-beam-scanned optical disc includes an information recording area and an information management area. The information management area stores recording management information having portions corresponding to respective integer multiples of a normal velocity relating to scanning of the disc. Each of the portions of the recording management information contains a first information piece representative of a recording strategy for recording of information on the information recording area and a second information piece representative of a recording laser power for recording of information on the information recording area.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of application Ser. No. 10/280,010filed Oct. 25, 2002, now U.S. Pat. No. 7,102,970.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an optical disc. In addition, this inventionrelates to an apparatus for recording and reproducing information on andfrom an optical disc. Furthermore, this invention relates to a method ofrecording and reproducing information on and from an optical disc.

2. Description of the Related Art

Optical discs are of a read only type (a playback only type), arecordable type (a write once type), and a rewritable type. A CD(Compact Disc), a VCD (Video CD), and a DVD (Digital Versatile Disc) areoptical discs of the read only type. A CD-R and a DVD-R are opticaldiscs of the recordable type. A CD-RW, a DVD-RAM, and a DVD-RW areoptical discs of the rewritable type.

Optical discs of the rewritable type have thin recording films which arereversibly changed between two or more different states in accordancewith conditions of laser beams applied thereto. Rewritable optical discsinclude magneto-optical discs and phase change discs.

In the case of a phase change optical disc, while a recording film isscanned by a laser beam, the recording film is reversibly changedbetween an amorphous state and a crystalline state by varying conditionsof the laser beam in response to a signal to be recorded. Thus, thesignal is recorded on the recording film as a pattern of amorphousportions and crystalline portions of the recording film. The signal isreproduced from the phase change optical disc as follows. The surface ofan amorphous portion of the disc and the surface of a crystallineportion thereof are different in reflectivity with respect to a laserbeam. While the phase change optical disc is scanned by a laser beam, achange in reflectivity of the disc surface with respect to the laserbeam is optically detected so that the signal is reproduced from thedisc.

The phase change optical disc is similar to a read only optical disc anda recordable optical disc in the point that the signal reproduction isimplemented by detecting a change in the disc surface reflectivity withrespect to a laser beam. The signal overwriting on the phase changeoptical disc can be performed by use of only one laser beam when thelaser power is modulated between an erasing level and a recording level.Therefore, the structure of a drive device for the phase change opticaldisc can be simple.

A PWM (pulse width modulation) system is used to record a signal on arewritable optical disc at a high density. According to the PWM system,the positions of the front and rear edges of every recording mark on thedisc correspond to “1” in a digital signal.

Conditions of a rewritable optical disc, such as the composition ofmaterial for the disc, an additive to the material, and a film thicknessin the disc, depend on the maker which has produced the disc.Accordingly, an optimal recording power of a laser beam applied to arewritable optical disc, an optimal erasing power of the laser beam, adesired width of a front end pulse in a pulse group, a desired width ofintermediate multiple pulses in the pulse group, and a desired width ofa rear end pulse in the pulse group vary from disc maker to disc maker.In general, information about an optimal recording power, an optimalerasing power of the laser beam, and desired pulse widths which varyfrom disc maker to disc maker is recorded on each rewritable opticaldisc as pre-pits.

In the PWM system, the width of every recording mark representsinformation. Thus, a desirable shape of the recording mark is free fromdistortion. Specifically, it is desirable that the shapes of the frontand rear halves of the recording mark are symmetrical with each other.During the PWM-based recording of a signal on the disc, the disc isexposed to a laser beam while being rotated and moved relative thereto.In addition, the intensity of the laser beam is changed between strongand weak levels in response to the signal to be recorded. Recordingmarks are formed on portions of the disc which are exposed to and heatedby the stronger laser beam. Regarding every recording mark, the heataccumulation effect causes the stronger-beam-application ending point onthe disc to be higher in temperature than the stronger-beam-applicationstarting point on the disc. As a result, the rear end of the recordingmark is wider than the front end thereof. Thus, the shape of therecording mark is distorted.

A known drive apparatus for a rewritable optical disc records a signalon the disc by use of a laser beam while driving and rotating the discrelative to the laser beam at a constant linear velocity which can beselected from a predetermined normal velocity and a predetermined highvelocity. The normal velocity is equal to, for example, 3.49 m/s. Thehigh velocity is equal to, for example, twice or four times the normalvelocity.

Since the recording of a signal on a rewritable optical disc by a laserbeam is based on heating, recording conditions change in accordance withthe velocity (the speed) at which the disc is driven and rotatedrelative to the laser beam. Accordingly, an optimal recording power ofthe laser beam, an optimal erasing power of the laser beam, a desiredwidth of a front end pulse in a pulse group, a desired width ofintermediate multiple pulses in the pulse group, and a desired width ofa rear end pulse in the pulse group depend on the drive speed of thedisc relative to the laser beam.

A desired width of a front end pulse in a pulse group, a desired widthof intermediate multiple pulses in the pulse group, and a desired widthof a rear end pulse in the pulse group are time information referred toas strategy. It is known that information about an optimal recordingpower of a laser beam, information about an optimal erasing power of thelaser beam, and strategy for a normal disc drive speed (a normal discscanning speed) are recorded on a rewritable optical disc as pre-pits.On the other hand, it is not known to record laser-power information andstrategy for a high disc drive speed (a high disc scanning speed) on arewritable optical disc as pre-pits.

In the case of a rewritable optical disc having pre-pits representingonly laser-power information and strategy for a normal disc scanningspeed, it takes a long time to find optimal recording conditions for ahigh disc scanning speed and then start the recording of a signal on thedisc under the optimal recording conditions.

U.S. Pat. No. 6,404,713 B1 corresponding to Japanese patent applicationpublication number P2001-209940A discloses a first apparatus forrecording and reproducing an information signal on and from an opticaldisc. The first apparatus includes a memory. The information signal iswritten into the memory. The information signal is read out from thememory. An optical head generates a laser beam in response to thereadout information signal, and applies the laser beam to the opticaldisc to record the readout information signal on the optical disc. Atest signal is recorded on a position of the optical disc near arecording position thereof via the optical head during the writing ofthe information signal into the memory. The test signal is reproducedfrom the optical disc. The reproduced test signal is evaluated togenerate an evaluation result. An intensity of the laser beam isoptimized in response to the evaluation result.

U.S. Pat. No. 6,404,713 B1 also discloses a second apparatus forrecording and reproducing an information signal on and from an opticaldisc. The second apparatus includes a memory. The information signal iswritten into the memory. The information signal is read out from thememory. An optical head generates a laser beam in response to thereadout information signal, and applies the laser beam to the opticaldisc to record the readout information signal on the optical disc. Apower of the laser beam is changed among a plurality of differentlevels. The laser beam is measured to generate measurement result valuesduring the change of the power of the laser beam among the plurality ofthe different levels. An intensity of the laser beam is optimized inresponse to the measurement result values.

SUMMARY OF THE INVENTION

It is a first object of this invention to provide an optical disc whichenables a recording apparatus to quickly start the recording of a signalon the disc at a high disc scanning speed.

It is a second object of this invention to provide an apparatus forrecording and reproducing information on and from an optical disc whichcan quickly start the recording of a signal on the disc at a high discscanning speed.

It is a third object of this invention to provide a method of recordingand reproducing information on and from an optical disc which canquickly start the recording of a signal on the disc at a high discscanning speed.

A first aspect of this invention provides a laser-beam-scanned opticaldisc including an information recording area and an informationmanagement area, the information management area storing recordingmanagement information having portions corresponding to respectiveinteger multiples of a normal velocity relating to scanning of the disc,wherein each of the portions of the recording management informationcontains a first information piece representative of a recordingstrategy for recording of information on the information recording areaand a second information piece representative of a recording laser powerfor recording of information on the information recording area.

A second aspect of this invention provides a laser-beam-scanned opticaldisc including an information recording area and an informationmanagement area, wherein units of signal recording and signalreproduction on and from at least one of the information recording areaand the information management area are blocks including first blockseach duplicately having a block address and second blocks each havingboth a block address and a management information piece, the informationrecording area storing blocks among the first blocks, the informationmanagement area storing the second blocks having recording managementinformation including portions corresponding to respective integermultiples of a normal velocity relating to scanning of the disc, whereineach of the portions of the recording management information contains afirst information piece representative of a recording strategy forrecording of information on the information recording area and a secondinformation piece representative of a recording laser power forrecording of information on the information recording area.

A third aspect of this invention is based on the first aspect thereof,and provides a laser-beam-scanned optical disc wherein the informationmanagement area recurrently stores a whole of the portions of therecording management information which correspond to the integermultiples of the normal velocity respectively.

A fourth aspect of this invention provides a laser-beam-scanned opticaldisc including an information recording area and an informationmanagement area, wherein units of signal recording and signalreproduction on and from at least one of the information recording areaand the information management area are blocks including first blockseach duplicately having a block address and second blocks each havingboth a block address and a management information piece, the informationrecording area storing blocks among the first blocks, the informationmanagement area storing the second blocks recurrently having recordingmanagement information including portions corresponding to respectiveinteger multiples of a normal velocity relating to scanning of the disc,wherein each of the recording management information contains a firstinformation piece representative of a recording strategy for recordingof information on the information recording area and a secondinformation piece representative of a recording laser power forrecording of information on the information recording area, theinformation management area having a portion unoccupied by blocks amongthe second blocks and occupied by blocks among the first blocks.

A fifth aspect of this invention provides an apparatus for recording andreproducing information on and from a laser-beam-scanned optical discincluding an information recording area and an information managementarea, the information management area storing recording managementinformation having portions corresponding to respective integermultiples of a normal velocity relating to scanning of the disc, whereineach of the portions of the recording management information contains afirst information piece representative of a recording strategy forrecording of information on the information recording area and a secondinformation piece representative of a recording laser power forrecording of information on the information recording area. Theapparatus comprises first means for reading, from the informationmanagement area of the disc, one of the portions of the recordingmanagement information which corresponds to desired one of the normalvelocity and the at least one integer multiple of the normal velocity;second means for setting an actual recording strategy and an actualrecording power of a laser beam in accordance with the recordingstrategy and the recording laser power represented by the portion of therecording management information which is read by the first means; andthird means for recording information on the information recording areaof the disc by use of the laser beam having the actual recordingstrategy and the actual recording power set by the second means.

A sixth aspect of this invention provides an apparatus for recording andreproducing information on and from a laser-beam-scanned optical discincluding an information recording area and an information managementarea, wherein units of signal recording and signal reproduction on andfrom at least one of the information recording area and the informationmanagement area are blocks including first blocks each duplicatelyhaving a block address and second blocks each having both a blockaddress and a management information piece, the information recordingarea storing blocks among the first blocks, the information managementarea storing the second blocks having recording management informationincluding portions corresponding to respective integer multiples of anormal velocity relating to scanning of the disc, wherein each of theportions of the recording management information contains a firstinformation piece representative of a recording strategy for recordingof information on the information recording area and a secondinformation piece representative of a recording laser power forrecording of information on the information recording area. Theapparatus comprises first means for reading, from the informationmanagement area of the disc, one of the portions of the recordingmanagement information which corresponds to desired one of the normalvelocity and the at least one integer multiple of the normal velocity;second means for setting an actual recording strategy and an actualrecording power of a laser beam in accordance with the recordingstrategy and the recording laser power represented by the portion of therecording management information which is read by the first means; andthird means for recording information on the information recording areaof the disc by use of the laser beam having the actual recordingstrategy and the actual recording power set by the second means.

A seventh aspect of this invention provides an apparatus for recordingand reproducing information on and from a laser-beam-scanned opticaldisc including an information recording area and an informationmanagement area, wherein units of signal recording and signalreproduction on and from at least one of the information recording areaand the information management area are blocks including first blockseach duplicately having a block address and second blocks each havingboth a block address and a management information piece, the informationrecording area storing blocks among the first blocks, the informationmanagement area storing the second blocks recurrently having recordingmanagement information including portions corresponding to respectiveinteger multiples of a normal velocity relating to scanning of the disc,wherein each of the recording management information contains a firstinformation piece representative of a recording strategy for recordingof information on the information recording area and a secondinformation piece representative of a recording laser power forrecording of information on the information recording area, theinformation management area having a portion unoccupied by blocks amongthe second blocks and occupied by blocks among the first blocks. Theapparatus comprises first means for reading, from the informationmanagement area of the disc, one of the portions of the recordingmanagement information which corresponds to desired one of the normalvelocity and the at least one integer multiple of the normal velocity;second means for setting an actual recording strategy and an actualrecording power of a laser beam in accordance with the recordingstrategy and the recording laser power represented by the portion of therecording management information which is read by the first means; andthird means for recording information on the information recording areaof the disc by use of the laser beam having the actual recordingstrategy and the actual recording power set by the second means.

An eighth aspect of this invention provides a method of recording andreproducing information on and from a laser-beam-scanned optical discincluding an information recording area and an information managementarea, the information management area storing recording managementinformation having portions corresponding to respective integermultiples of a normal velocity relating to scanning of the disc, whereineach of the portions of the recording management information contains afirst information piece representative of a recording strategy forrecording of information on the information recording area and a secondinformation piece representative of a recording laser power forrecording of information on the information recording area. The methodcomprises the steps of reading, from the information management area ofthe disc, one of the portions of the recording management informationwhich corresponds to desired one of the normal velocity and the at leastone integer multiple of the normal velocity; setting an actual recordingstrategy and an actual recording power of a laser beam in accordancewith the recording strategy and the recording laser power represented bythe portion of the recording management information which is read; andrecording information on the information recording area of the disc byuse of the laser beam having the actual recording strategy and theactual recording power which are set.

A ninth aspect of this invention provides a method of recording andreproducing information on and from a laser-beam-scanned optical discincluding an information recording area and an information managementarea, wherein units of signal recording and signal reproduction on andfrom at least one of the information recording area and the informationmanagement area are blocks including first blocks each duplicatelyhaving a block address and second blocks each having both a blockaddress and a management information piece, the information recordingarea storing blocks among the first blocks, the information managementarea storing the second blocks having recording management informationincluding portions corresponding to respective integer multiples of anormal velocity relating to scanning of the disc, wherein each of theportions of the recording management information contains a firstinformation piece representative of a recording strategy for recordingof information on the information recording area and a secondinformation piece representative of a recording laser power forrecording of information on the information recording area. The methodcomprises the steps of reading, from the information management area ofthe disc, one of the portions of the recording management informationwhich corresponds to desired one of the normal velocity and the at leastone integer multiple of the normal velocity; setting an actual recordingstrategy and an actual recording power of a laser beam in accordancewith the recording strategy and the recording laser power represented bythe portion of the recording management information which is read; andrecording information on the information recording area of the disc byuse of the laser beam having the actual recording strategy and theactual recording power which are set.

A tenth aspect of this invention provides a method of recording andreproducing information on and from a laser-beam-scanned optical discincluding an information recording area and an information managementarea, wherein units of signal recording and signal reproduction on andfrom at least one of the information recording area and the informationmanagement area are blocks including first blocks each duplicatelyhaving a block address and second blocks each having both a blockaddress and a management information piece, the information recordingarea storing blocks among the first blocks, the information managementarea storing the second blocks recurrently having recording managementinformation including portions corresponding to respective integermultiples of a normal velocity relating to scanning of the disc, whereineach of the recording management information contains a firstinformation piece representative of a recording strategy for recordingof information on the information recording area and a secondinformation piece representative of a recording laser power forrecording of information on the information recording area, theinformation management area having a portion unoccupied by blocks amongthe second blocks and occupied by blocks among the first blocks. Themethod comprises the steps of reading, from the information managementarea of the disc, one of the portions of the recording managementinformation which corresponds to desired one of the normal velocity andthe at least one integer multiple of the normal velocity; setting anactual recording strategy and an actual recording power of a laser beamin accordance with the recording strategy and the recording laser powerrepresented by the portion of the recording management information whichis read; and recording information on the information recording area ofthe disc by use of the laser beam having the actual recording strategyand the actual recording power which are set.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a time-domain diagram of a waveform of data to be recorded,and a recording waveform of a laser beam.

FIG. 2 is a diagram of the format of an LPP-information field system foran optical disc designed to be scanned at only a normal linear velocity.

FIG. 3 is a diagram of the format of an LPP-information field system foran optical disc designed to be scanned at a linear velocity selectablefrom a normal linear velocity and higher linear velocities.

FIG. 4 is a diagram of the details of a field ID0 which is listed inFIG. 2 or FIG. 3.

FIG. 5 is a diagram of the details of a field ID2 which is listed inFIG. 2 or FIG. 3.

FIG. 6 is a diagram of the details of a field ID5 which is listed inFIG. 2 or FIG. 3.

FIG. 7 is a diagram of the details of a field IDn which is listed inFIG. 3.

FIG. 8 is a diagram of the details of a field IDn+1 which is listed inFIG. 3.

FIG. 9 is a sectional diagram of an optical disc in a first embodimentof this invention.

FIG. 10 is a perspective view, partially in section, of a portion of anoptical disc in the first embodiment of this invention.

FIG. 11 is a diagram of the arrangement of fields ID0, ID1, ID2, . . . ,and IDn+1 in the lead-in area and the data area of an optical disc inthe first embodiment of this invention.

FIG. 12 is a block diagram of an information-signal recording andreproducing apparatus in the first embodiment of this invention.

FIG. 13 is a block diagram of an amplifier unit in FIG. 12.

FIG. 14 is a block diagram of an example of a waveform correctioncircuit in FIG. 13.

FIG. 15 is a sectional diagram of an optical disc in a second embodimentof this invention.

FIG. 16 is a diagram of the details of a field “1” of an RMD area inFIG. 15.

DETAILED DESCRIPTION OF THE INVENTION First Embodiment

According to a first embodiment of this invention, a signal is recordedon and reproduced from an optical disc while the disc is scanned by arecording laser beam or a reproducing laser beam. The scanning of thedisc by the laser beam is on a CLV (constant linear velocity) basis. Theconstant linear velocity relating to the scanning of the disc can beselected from a predetermined normal velocity and at least onepredetermined high velocity. The normal velocity is equal to, forexample, 3.49 m/s. The high velocity is equal to an integer multiple ofthe normal velocity. The first embodiment of this invention is designedto correct a recording laser beam into an optimal waveform in accordancewith the type of an optical disc and a change in the linear velocityrelating to the scanning of the disc.

As shown in FIG. 1, data to be recorded, that is, 8-16modulation-resultant input data, repetitively change between a highlevel state and a low level state. The input data continuously in thehigh level state correspond to a recording mark on an optical disc. Theinput data continuously in the low level state correspond to a spacebetween recording marks on the optical disc. A laser beam for writinginformation on an optical disc (for example, a DVD-RW) is modulated intoa recording waveform in accordance with the input data. A clock signal(a bit clock signal) related to the input data has a period T. Theperiod T is also indicated as T. The input data in FIG. 1 have atime-domain portion with a mark length of 8T, and a time-domain portionwith a mark length of 3T. According to the laser-beam recording waveformwhich corresponds to the 8T mark portion or the 3T mark portion of theinput data, the power (or the intensity) of the laser beam changes amonga recording level Po, an erasing level Pe, and a bias level Pb. Therecording level Po is greater than the erasing level Pe. The erasinglevel Pe is greater than the bias level Pb.

As shown in FIG. 1, for the 8T mark portion or the 3T mark portion ofthe input data, the power of the laser beam initially remains equal tothe erasing level Pe during a certain time length and then rises to therecording level Po to form a first positive-going pulse. Thereafter, thepower of the laser beam alternately changes between the recording levelPo and the bias level Pb to form a second positive-going pulse or secondand later positive-going pulses referred to as multiple positive-goingpulses. Preferably, the second and later positive-going pulses have asame width. At the end of the 8T mark portion or the 3T mark portion ofthe input data, the power of the laser beam drops from the recordinglevel Po to the bias level Pb, and the last positive-going pulseterminates. The last positive-going pulse is followed by anegative-going pulse serving as a cooling pulse. Specifically, after theend of the 8T mark portion or the 3T mark portion of the input data, thepower of the laser beam remains equal to the bias level Pb during acertain time length and then rises to the erasing level Pe to form thecooling pulse.

With reference to FIG. 1, during the first T range of the 8T markportion or the 3T mark portion of the input data, a positive-going pulseis absent. There is one positive-going pulse corresponding to each ofthe second and later T ranges of the 8T mark portion or the 3T markportion of the input data. The bias level Pb is equal to a reproducinglevel in the case of a DVD-RW. A strategy for optimal recording whichrelates to recording pulse timings is designed to optimally decide thewidth Ttop of the first positive-going pulse, the width (the duty cycle)Tmp of the second and later positive-going pulses, and the width Tcl ofthe cooling pulse. For mark portions of the input data which differ fromthe 8T mark portion and the 3T mark portion, the power of the laser beamis controlled similarly to the previously-mentioned laser-power controlfor the 8T mark portion and the 3T mark portion.

In the case of a DVD-R (an optical disc), the laser-power-relatedparameters are modified from those for a DVD-RW. Specifically, theerasing level Pe is changed to the reproducing level (the bias levelPb), and every cooling pulse is removed. The laser-power-relatedparameters for a DVD-R may be similar to those for a DVD-RW.

In the case of a DVD-RW, the multiple-pulse-like change of thelaser-beam power between the recording level Po and the reproducinglevel (the bias level Pb) may be replaced by a laser-power controlprofile causing the laser-beam power in an intermediate time range to belower than those in first and last time ranges for every mark portion ofthe input data. This design also provides a strategy for optimalrecording. The level of the laser-beam power in the intermediate timerange is optimally decided. Furthermore, the timing of drop of thelaser-beam power for the intermediate time range is optimally decided.

The laser-power-related parameters for a DVD+RW (an optical disc) aresimilar to those for a DVD-RW. The laser-power-related parameters for aDVD+R (an optical disc) are similar to those for a DVD-R. Thelaser-power-related parameters for a Blu-ray-standard disc are similarto those for a DVD-RW.

A DVD-R or a DVD-RW has a lead-in area and a data area on whichinformation can be recorded. In general, the lead-in area and the dataarea correspond to an information management area and an informationrecording area, respectively. The lead-in area and the data area areformed with an information-recording groove track which wobbles at aconstant frequency. When the normal linear velocity relating to thescanning of the disc is equal to 3.49 m/s, the wobble frequency is equalto about 140 kHz. In the lead-in area and the data area, lands betweengrooves or groove portions have land pre-pits (LPPs) representative ofaddress information and management information. Land pre-pits aredisclosed in, for example, Japanese patent application publicationnumber P2001-148124A or P2001-312823A.

A signal recorded on an optical disc such as a DVD-R or a DVD-RW isdivided into ECC blocks. One ECC block is a minimum unit of errorcorrection. Also, one ECC block is a minimum unit for the signalreproduction from and the signal recording on the optical disc. Each ofunits composing the information represented by the LPPs corresponds toone ECC block, and has an information piece representative of an addressand other information pieces. The units composing the LPP informationare referred to as fields classified by a field type ID (a field typeidentifier). The field type ID can change among ID0, ID1, ID2, . . . . Afield of a type corresponding to a field type IDk is called a field IDk,where IDk=ID0, ID1, ID2, . . . . As will be made clear later, everyfield is composed of 16 frames.

FIG. 2 shows the format of an LPP-information field system for anoptical disc designed to be scanned at only the normal linear velocity.As shown in FIG. 2, there are fields of six types denoted by ID0, ID1,ID2, ID3, ID4, and ID5 respectively. A field ID0 stores an informationpiece representative of the address of a corresponding ECC block, andother information pieces. Generally, the field ID0 is recorded on a dataarea of the disc. A field ID1 stores an information piece representativeof the address of a corresponding ECC block, an application code, andother information pieces. The field ID1 is recorded on a lead-in area ofthe disc. A field ID2 stores an information piece representative of theaddress of a corresponding ECC block, an OPC recommended code/writestrategy code “1”, and other information pieces. Here, OPC means“optimum power control”. The field ID2 is recorded on the lead-in areaof the disc. A field ID3 stores an information piece representative ofthe address of a corresponding ECC block, a production ID “1”, and otherinformation pieces. The field ID3 is recorded on the lead-in area of thedisc. A field ID4 stores an information piece representative of theaddress of a corresponding ECC block, a production ID “2”, and otherinformation pieces. The field ID4 is recorded on the lead-in area of thedisc. A field ID5 stores an information piece representative of theaddress of a corresponding ECC block, a write strategy code “2”, andother information pieces. The field ID5 is recorded on the lead-in areaof the disc.

FIG. 3 shows the format of an LPP-information field system for anoptical disc designed to be scanned at a linear velocity selectable fromthe normal linear velocity, a velocity equal to twice the normal linearvelocity (the 2-fold linear velocity), . . . , and a linear velocityequal to “m” times the normal linear velocity (the m-fold linearvelocity), where “m” denotes a predetermined natural number equal to orgreater than 4. For example, the disc scanning linear velocity can beselected from the 1-fold linear velocity (the normal linear velocity),the 2-fold linear velocity, the 4-fold linear velocity, the 6-foldlinear velocity, the 8-fold linear velocity, the 12-fold linearvelocity, the 16-fold linear velocity, and the 24-fold linear velocity.As shown in FIG. 3, there are fields of different types denoted by ID0,ID1, ID2, . . . , IDn, and IDn+1 respectively. Fields ID0, ID1, ID2,ID3, ID4, and ID5 in FIG. 3 are similar to those in FIG. 2. Withreference to FIG. 3, a field ID2 stores an information piecerepresentative of the address of a corresponding ECC block, an OPCrecommended code/write strategy code “1” for the scanning of the disc atthe normal linear velocity, and other information pieces. A field ID5stores an information piece representative of the address of acorresponding ECC block, a write strategy code “2” for the scanning ofthe disc at the normal linear velocity, and other information pieces. Afield ID6 stores an information piece representative of the address of acorresponding ECC block, an OPC recommended code/write strategy code “1”for the scanning of the disc at the 2-fold linear velocity, and otherinformation pieces. The field ID6 is recorded on the lead-in area of thedisc. A field ID7 stores an information piece representative of theaddress of a corresponding ECC block, a write strategy code “2” for thescanning of the disc at the 2-fold linear velocity, and otherinformation pieces. The field ID7 is recorded on the lead-in area of thedisc. Similarly, a field IDn stores an information piece representativeof the address of a corresponding ECC block, an OPC recommendedcode/write strategy code “1” for the scanning of the disc at the m-foldlinear velocity, and other information pieces. The field IDn is recordedon the lead-in area of the disc. A field IDn+1 stores an informationpiece representative of the address of a corresponding ECC block, awrite strategy code “2” for the scanning of the disc at the m-foldlinear velocity, and other information pieces. The field IDn+1 isrecorded on the lead-in area of the disc.

FIG. 4 shows the details of a field ID0 which is listed in FIG. 2 orFIG. 3. In general, the field ID0 is recorded on the data area of thedisc. With reference to FIG. 4, the field ID0 is divided into 16 framesassigned numbers of “0”, “1”, . . . , and “15” respectively. In thefield ID0, the frames having numbers of “0”, “1”, and “2” store aninformation piece representative of the address of a corresponding ECCblock. The frames having numbers of “3”, “4”, and “5” store aninformation piece representative of the parity of the ECC-block-addressinformation piece. The frame having a number of “6” stores aninformation piece representative of a field ID value (a fieldidentification value). The frames having numbers of “7”, “8”, and “9”store an information piece representative of the address of thecorresponding ECC block. The frames having numbers of “10”, “11”, and“12” are reserved. The frames having numbers of “13”, “14”, and “15”store an information piece representative of the parity of theECC-block-address information piece. Thus, the field ID0 duplicatelystores the information piece representative of the address of thecorresponding ECC block.

As shown in FIG. 4, the 16 frames of the field ID0 are separated intotwo groups referred to as a part “A” and a part “B” respectively. Thepart “A” contains an information piece representative of the address ofa corresponding ECC block, and an information piece representative ofthe parity of the ECC-block-address information piece. The part “B”contains an information piece or information pieces peculiar to therelated field. Specifically, the part “A” stores an information piecerepresentative of the address of a corresponding ECC block, and aninformation piece representative of the parity of the ECC-block-addressinformation piece. The part “B” stores an information piecerepresentative of a field ID value, an information piece representativeof the address of the corresponding ECC block, and an information piecerepresentative of the parity of the ECC-block-address information piece.

Similarly, each of fields ID1, ID2, . . . , IDn, and IDn+1 which arelisted in FIG. 2 or FIG. 3 is divided into 16 frames assigned numbers of“0”, “1”, . . . , and “15” respectively. The 16 frames are separatedinto two groups referred to as a part “A” and a part “B” respectively.The part “A” contains an information piece representative of the addressof a corresponding ECC block, and an information piece representative ofthe parity of the ECC-block-address information piece. The part “B”contains an information piece or information pieces peculiar to therelated field.

The part “B” of a field ID1 stores an information piece representativeof a field ID value, an application code, and a physical code. Theapplication code has an information piece representative of general useof the disc, and an information piece representative of special use ofthe disc. The physical code has physical-specification informationpieces including an information piece representative of the track pitchof the disc, an information piece representative of the linear velocityrelating to the scanning of the disc, an information piecerepresentative of the diameter of the disc, an information piecerepresentative of the recording type (an information piecerepresentative of whether or not the disc is of the phase change type),and an information piece representative of whether the disc isrecordable or rewritable. The part “B” of a field ID3 or ID4 stores aninformation piece representative of a field ID value, and an informationpiece representative of an identification number (an ID number) of themaker or manufacturer of the disc.

FIG. 5 shows the details of a field ID2 which is listed in FIG. 2 orFIG. 3. In the field ID2, the frames having numbers of “6”-“15” areassigned to the part “B”. As shown in FIG. 5, the frame having a numberof “6” stores an information piece representative of a field ID value.The frames having numbers of “7” and “8” store an OPC recommended code.The frames having numbers of “9”, “10”, “11”, and “12” store a writestrategy code “1”. The frames having numbers of “13”, “14”, and “15”store an information piece representative of the parity of at least oneof the information pieces in the part “B”. The parity may be omitted. Inthis case, the frames having numbers of “13”, “14”, and “15” are set asreserved ones.

The OPC recommended code indicates a recording power level Po and anerasing power level Pe recommended by the disc maker (the discmanufacturer). The OPC recommended code may further indicate arecommended bias power level Pb. The OPC recommended code may indicatethe ratio ε=Pe/Po, that is, the ratio of the recommended erasing powerlevel Pe to the recommended recording power level Po. The OPCrecommended code may further indicate record optimizing informationincluding a recommended asymmetry value or a value β representative ofthe position of a short mark portion relative to a long mark portion ofan 8-16 modulation-resultant signal reproduced from the disc to deciderecording conditions. The write strategy code “1” has time informationpieces representative of recommended pulse widths Ttop, Tmp, and Tcl inthe strategy of FIG. 1.

FIG. 6 shows the details of a field ID5 which is listed in FIG. 2 orFIG. 3. In the field ID5, the frames having numbers of “6”-“15” areassigned to the part “B”. As shown in FIG. 6, the frame having a numberof “6” stores an information piece representative of a field ID value.The frames having numbers of “7”, “8”, “9”, and “10” store a writestrategy code “2”. The frames having numbers of “11” and “12” store aninformation piece representative of a desired disc scanning velocityvalue (1×). The frames having numbers of “13”, “14”, and “15” store aninformation piece representative of the parity of at least one of theinformation pieces in the part “B”. The parity may be omitted. In thiscase, the frames having numbers of “13”, “14”, and “15” are set asreserved ones. The write strategy code “2” has time information piecesrepresentative of recommended pulse widths Ttop, Tmp, and Tcl in astrategy using a predetermined recording waveform different from that inFIG. 1.

In general, the desired disc scanning velocity value (1×) indicates whattimes the normal linear velocity the disc can be scanned at.

The desired disc scanning velocity value (1×) is equal to the normallinear velocity relating to the scanning of the disc. When the normallinear velocity is equal to 3.49 m/s, the desired disc scanning velocityvalue (1×) is a numerical value of “3.49”. Alternatively, the desireddisc scanning velocity value (1×) may be “1” which is a multiplier forthe normal linear velocity. The desired disc scanning velocity value(1×) may be a hexadecimal coded value of “1” (a multiplier) or “3.49”.

Preferably, frames in each of the present field (ID5) and later fieldswhich are assigned to desired disc scanning velocity values furtherstore record optimizing information including a recommended asymmetryvalue or a value β representative of the position of a short markportion relative to a long mark portion of an 8-16 modulation-resultantsignal reproduced from the disc to decide recording conditions. Therecord optimizing information may also be in an OPC recommended code.

As the total number of different linear velocities from which thescanning velocity of an optical disc can be selected increases, thetotal number of the fields ID2 and ID5 and similar fields increases. Therecorded contents of the fields ID2 and ID5 correspond to the normallinear velocity relating to the scanning of the disc. In the case of anoptical disc designed to be scanned at only the normal linear velocity,an information piece representative of a desired disc scanning velocityvalue (1×) may be absent from the field ID5.

As previously mentioned, the fields ID0, ID1, ID2, ID3, ID4, and ID5 inFIG. 3 are similar to those in FIG. 2. The recorded contents of thefields ID2 and ID5 in FIG. 3 correspond to the normal linear velocityrelating to the scanning of the disc.

FIG. 7 shows the details of a field IDn which is listed in FIG. 3.

When “n” is equal to “6”, the field IDn in FIG. 7 is a field ID6. In thefield ID6, the frames having numbers of “6”-“15” are assigned to thepart “B”. As shown in FIG. 7, the frame having a number of “6” stores aninformation piece representative of a field ID value. The frames havingnumbers of “7” and “8” store an OPC recommended code for the 2-foldlinear velocity relating to the scanning of the disc. The frames havingnumbers of “9”, “10”, “11”, and “12” store a write strategy code “1” forthe 2-fold linear velocity relating to the scanning of the disc. Theframes having numbers of “13”, “14”, and “15” store an information piecerepresentative of the parity of at least one of the information piecesin the part “B”. The parity may be omitted. In this case, the frameshaving numbers of “13”, “14”, and “15” are set as reserved ones. The OPCrecommended code indicates a recording power level Po and an erasingpower level Pe recommended by the disc maker for the 2-fold linearvelocity relating to the scanning of the disc. The OPC recommended codemay also indicate a recommended bias power level Pb for the 2-foldlinear velocity relating to the scanning of the disc. The OPCrecommended code may further indicate record optimizing informationincluding a recommended asymmetry value or a value β representative ofthe position of a short mark portion relative to a long mark portion ofan 8-16 modulation-resultant signal reproduced from the disc to deciderecording conditions for the 2-fold linear velocity relating to thescanning of the disc. The write strategy code “1” has time informationpieces representative of recommended pulse widths Ttop, Tmp, and Tcl inthe strategy of FIG. 1 for the 2-fold linear velocity relating to thescanning of the disc.

FIG. 8 shows the details of a field IDn+1 which is listed in FIG. 3.When “n+1” is equal to “7”, the field IDn+1 in FIG. 8 is a field ID7.

In the field ID7, the frames having numbers of “6”-“15” are assigned tothe part “B”. As shown in FIG. 8, the frame having a number of “6”stores an information piece representative of a field ID value. Theframes having numbers of “7”, “8”, “9”, and “10” store a write strategycode “2” for the 2-fold linear velocity relating to the scanning of thedisc. The frames having numbers of “11” and “12” store an informationpiece representative of a desired disc scanning velocity value (2×)equal to the 2-fold linear velocity, that is, equal to twice the normallinear velocity relating to the scanning of the disc. The frames havingnumbers of “13”, “14”, and “15” store an information piecerepresentative of the parity of at least one of the information piecesin the part “B”. The parity may be omitted. In this case, the frameshaving numbers of “13”, “14”, and “15” are set as reserved ones. Thewrite strategy code “2” has time information pieces representative ofrecommended pulse widths Ttop, Tmp, and Tcl in a strategy using apredetermined recording waveform different from that in FIG. 1 for the2-fold linear velocity relating to the scanning of the disc.

With reference back to FIG. 7, in the field IDn, the frames havingnumbers of “6”-“15” are assigned to the part “B”. As shown in FIG. 7,the frame having a number of “6” stores an information piecerepresentative of a field ID value. The frames having numbers of “7” and“8” store an OPC recommended code for the m-fold linear velocityrelating to the scanning of the disc. The frames having numbers of “9”,“10”, “11”, and “12” store a write strategy code “1” for the m-foldlinear velocity relating to the scanning of the disc. The frames havingnumbers of “13”, “14”, and “15” store an information piecerepresentative of the parity of at least one of the information piecesin the part “B”. The parity may be omitted. In this case, the frameshaving numbers of “13”, “14”, and “15” are set as reserved ones. The OPCrecommended code indicates a recording power level Po and an erasingpower level Pe recommended by the disc maker for the m-fold linearvelocity relating to the scanning of the disc. The OPC recommended codemay also indicate a recommended bias power level Pb for the m-foldlinear velocity relating to the scanning of the disc. The OPCrecommended code may further indicate record optimizing informationincluding a recommended asymmetry value or a value β representative ofthe position of a short mark portion relative to a long mark portion ofan 8-16 modulation-resultant signal reproduced from the disc to deciderecording conditions for the m-fold linear velocity relating to thescanning of the disc. The write strategy code “1” has time informationpieces representative of recommended pulse widths Ttop, Tmp, and Tcl inthe strategy of FIG. 1 for the m-fold linear velocity relating to thescanning of the disc.

With reference to FIG. 8, in the field IDn+1, the frames having numbersof “6”-“15” are assigned to the part “B”. As shown in FIG. 8, the framehaving a number of “6” stores an information piece representative of afield ID value. The frames having numbers of “7”, “8”, “9”, and “10”store a write strategy code “2” for the m-fold linear velocity relatingto the scanning of the disc. The frames having numbers of “11” and “12”store an information piece representative of a desired disc scanningvelocity value (mX) equal to the m-fold linear velocity, that is, equalto “m” times the normal linear velocity relating to the scanning of thedisc. The frames having numbers of “13”, “14”, and “15” store aninformation piece representative of the parity of at least one of theinformation pieces in the part “B”. The parity may be omitted. In thiscase, the frames having numbers of “13”, “14”, and “15” are set asreserved ones. The write strategy code “2” has time information piecesrepresentative of recommended pulse widths Ttop, Tmp, and Tcl in astrategy using a predetermined recording waveform different from that inFIG. 1 for the m-fold linear velocity relating to the scanning of thedisc.

In this way, as the total number of different linear velocities fromwhich the scanning velocity of an optical disc can be selected increasesby one, the total number of field types increases by two. For an opticaldisc designed to be scanned at a linear velocity selectable from thenormal linear velocity and the 2-fold linear velocity, there are fieldsID0 to ID7. For an optical disc designed to be scanned at a linearvelocity selectable from the normal linear velocity, the 2-fold linearvelocity, and the 4-fold linear velocity, there are fields ID0 to ID9.For an optical disc designed to be scanned at a linear velocityselectable from the normal linear velocity, the 2-fold linear velocity,the 4-fold linear velocity, and the m-fold linear velocity, there arefields ID0 to IDn+1. The total number of ID0 to IDn+1 indicates thetotal number of different linear velocities from which the scanningvelocity of an optical disc can be selected.

Preferably, an application code in the field ID1 includes an extensioncode representing the total number of different linear velocities fromwhich the scanning velocity of an optical disc can be selected. For anoptical disc storing only fields ID0 to ID5, the extension code is setto “0” which represents that the disc can be scanned at only the normallinear velocity. For an optical disc storing only fields ID0 to ID7, theextension code is set to “2” which represents that the disc can bescanned at a linear velocity selectable from the normal linear velocityand the 2-fold linear velocity. Thus, the extension code is set to avalue equal to the maximum number following “ID” minus “5”. For example,the extension code is set to “n-4” when the maximum number following“ID” is equal to “n+1”.

As previously mentioned, the total number of field types denoted by ID0,ID1, ID2, . . . increases in accordance with the total number ofdifferent linear velocities from which the scanning velocity of anoptical disc can be selected. This design enables a recording andreproducing apparatus to get optimal recording conditions, that is,optimal values about the setting of laser power, for each of thedifferent linear velocities relating to the scanning of the disc.

With reference to FIG. 9, an optical disc (for example, a DVD-RW)includes a lead-in area and a data area. The lead-in area extends in aninner portion of the disc. The data area extends outward of the lead-inarea. The lead-in area and the data area form an information managementarea and an information recording area, respectively. Information formanaging the recording and reproduction of data on and from the dataarea, and also information peculiar to the disc are recorded on thelead-in area. Data (for example, contents data or user data) can berecorded on and reproduced from the data area. In an optical disc whichhas not yet been subjected to the data recording, LPPs (land pre-pits)representative of an address signal and a management signal, and awobbling portion representative of a wobble signal are formed along agroove on a 1-ECC-block by 1-ECC-block basis.

The lead-in area of a DVD-RW includes a readable emboss area exclusivelyfor playback. The readable emboss area is formed with emboss pre-pits,and has only wobbling information. LPP information is absent from thereadable emboss area. In a DVD-R, a readable emboss area may be replacedwith a recordable and readable area. In this case, LPP informationexists on the recordable and readable area as LPP information exists onother portions of the lead-in area.

FIG. 10 shows a portion of an optical disc 101 such as a DVD-RW or aDVD-R. The optical disc 101 includes an information recording layer 105having a phase change film or a pigment film. The optical disc 101includes a metal-deposited layer (for example, a gold-deposited layer)106 which extends below the information recording layer 105 as viewed inFIG. 10. The metal-deposited layer 106 acts to reflect a light beam (alaser beam) 108.

The optical disc 101 has an information recording area formed with aspiral of a wobbling groove 102 and a spiral of a land 103. It should benoted that FIG. 10 illustrates the groove 102 and the land 103 in anopposite manner. Specifically, FIG. 10 illustrates the groove 102 andthe land 103 as those in a stamper for an optical disc. A portion of theland 103 is located between neighboring portions of the groove 102. Agroove portion and a pair of land portions adjoining the groove portioncompose a track portion. The groove 102 and the land 103 are coated witha protective film 107. For an easier understanding, groove portions,land portions, and track portions which neighbor in a radial directionof the optical disc 101 are also referred to as grooves, lands, andtracks, respectively.

Alternatively, the optical disc 101 may have a set of concentriccircular wobbling grooves 102 and lands 103 formed between neighboringgrooves 102.

Main information can be recorded on and reproduced from the groove (orthe grooves) 102. First auxiliary information is previously recorded onthe optical disc 101 as the wobble of the groove (or the grooves) 102.Second auxiliary information (pre-pit signals or land pre-pit signals)is previously recorded on the land (or the lands) 103. Specifically, thesecond auxiliary information is represented by land pre-pits (LPPs) 104,that is, pre-pits 104 formed in the land (or the lands) 103. The firstauxiliary information and the second auxiliary information are used forthe recording of main information on the optical disc 101 or thereproduction of main information therefrom.

The first auxiliary information contains a reference clock signal whichis used for the control of rotation of the optical disc 101. The secondauxiliary information contains address information (LPP addressinformation) from which the position of an arbitrary point on theoptical disc 101 can be detected. The second auxiliary information alsocontains management information for the signal recording on the opticaldisc 101.

During the recording of main information on the optical disc 101 or thereproduction of main information therefrom, the track is scanned by thelight beam 108 while the optical disc 101 is rotated. In this case, thewobble of the groove (or the grooves) 102 and the pre-pits 104 in theland (or the lands) 103 are detected. A wobble signal is generated inresponse to the detection of the wobble of the groove (or the grooves)102. The reference clock signal is reproduced from the wobble signal.Rotation of the optical disc 101 is controlled in response to thereproduced reference clock signal. LPP signals, that is, land pre-pitsignals, are generated in response to the detection of the pre-pits 104.The position of a currently-accessed point on the optical disc 101 isdetected from the LPP signals. Management information for the signalrecording on the optical disc 101 can be derived from the LPP signals.

The light beam 108 is focused into a light spot SP on the optical disc101. A tracking process forces the center of the light spot SP to movealong a substantial central line of the groove 102 during the rotationof the optical disc 101. The light spot SP extends over the groove 102of interest and also the lands 103 adjoining the groove 102 of theinterest. The light beam 108 is reflected by the optical disc 101,traveling back as a reflected light beam. The reflected light beam issensed by a photodetector. The photodetector has segments separated by aline parallel to the direction of rotation of the optical disc 101.According to a radial push-pull method using the photodetector, thesecond auxiliary information represented by the pre-pits 104 isreproduced from portions of the reflected light beam which correspond tothe light-spot portions extending over the lands 103. At the same time,the first auxiliary information represented by the wobble of the groove102 is reproduced from a portion of the reflected light beam whichcorresponds to the light-spot portion extending over the groove 102. Thereference clock signal is detected from the first auxiliary information.The reference clock signal is used for the control of rotation of theoptical disc 101.

FIG. 11 shows the arrangement of fields ID0, ID1, ID2, and IDn+1 in thelead-in area and the data area of an optical disc (for example, aDVD-RW). As shown in FIG. 11, a set of fields ID 1, ID2, . . . , andIDn+1 is recurrently placed in specified portions of the lead-in areabetween a lead-in start position and a lead-in end position (a lead-instart ECC block address “FFDD05h” and a lead-in end ECC block address“FFD000h”). Specifically, a set of fields ID1, ID2, . . . , and IDn+1 isrecurrently placed in a first lead-in area portion between the lead-instart position and a position immediately preceding a readable embossstart position, and a second lead-in area portion between a positionimmediately following a readable emboss end position and the lead-in endposition.

With reference to FIG. 11, fields ID0 are placed in the data area whichstarts from a data start position immediately following the lead-in endposition and having an ECC block address “FFCFFFh”.

As previously mentioned, each field ID0 duplicately stores aninformation piece representative of the address of a corresponding ECCblock. For an optical disc designed to be scanned at only the normallinear velocity, a set of fields ID1, ID2, . . . , and ID5 isrecurrently placed in the lead-in area. As the total number of differentlinear velocities from which the scanning velocity of an optical disccan be selected increases, the total number of fields ID1, ID2, . . .placed-in the lead-in area increases. Therefore, as the total number ofdifferent linear velocities from which the scanning velocity of anoptical disc can be selected increases, the number of the recurrence ofa set of fields ID1, ID2, . . . placed in the lead-in area decreases.All fields ID1, ID2, corresponding to different linear velocities fromwhich the scanning velocity of an optical disc can be selected areplaced in the lead-in area. Accordingly, the lead-in area can be usedwithout waste. Furthermore, at each of the different linear velocitiesrelating to the scanning of the disc, corresponding fields ID1, ID2, canbe quickly accessed.

As shown in FIG. 11, a field ID1 is placed at the lead-in startposition, and fields ID2, ID3, are successively placed at positionsfollowing the lead-in start position. A set of fields ID1, ID2, . . . ,and IDn+1 is recurrently placed in the lead-in area. In the case where aportion of the lead-in area between the position of a last field (aprovisional last field) IDn+1 and the lead-in end position isinsufficient to store a complete set of fields ID1, ID2, . . . , andIDn+1, that potion of the lead-in area is loaded with fields ID0. Aspreviously mentioned, each field ID0 duplicately stores an informationpiece representative of the address of a corresponding ECC block.

In some cases, the recording and reproduction of a signal on and fromthe data area of an optical disc are on a real-time basis. To reliablyimplement the signal recording and the signal reproduction, it isdesirable to surely read addresses represented by LPPs on the disc. Forthis reason, the data area is loaded with fields ID0, each of whichduplicately has an information piece of a corresponding LPP address (acorresponding ECC block address). Regarding the start of the recordingof a signal on the data area, it is desirable to surely read theaddresses of several ECC blocks in a portion of the lead-in area whichextends adjacently inward of the lead-in end position. As previouslymentioned, in the case where a portion of the lead-in area between theposition of a last field (a provisional last field) IDn+1 and thelead-in end position is insufficient to store a complete set of fieldsID1, ID2, . . . , and IDn+1, that potion of the lead-in area is loadedwith fields ID0. This design makes it possible to surely read theaddresses of several ECC blocks in a portion of the lead-in area whichextends adjacently inward of the lead-in end position since each fieldID0 duplicately has an information piece of a corresponding LPP address(a corresponding ECC block address).

The lead-in area of a DVD-RW includes a readable emboss area from whichLPP information is absent. Fields ID1, ID2, . . . , and IDn+1 are alsoabsent from the readable emboss area. In the case where a portion of thelead-in area between the position of a last field (a provisional lastfield) IDn+1 and the readable emboss start position is insufficient tostore a complete set of fields ID1, ID2, . . . , and IDn+1, that potionof the lead-in area is preferably loaded with fields ID0. According tothis design, it is possible to surely confirm or detect the readableemboss start position. Preferably, a portion of the lead-in area whichextends adjacently outward of the readable emboss end position, andwhich has a size corresponding to several tracks or several ECC blocksis loaded with fields ID0. This design makes it possible to surelyconfirm or detect the readable emboss end position.

A DVD-R having a lead-in area with a readable emboss area is similar tothe DVD-RW in arrangement of fields ID0, ID1, ID2, . . . , and IDn+1. Ina DVD-R including an LPP-added pre-recorded area instead of a readableemboss area, a set of fields ID1, ID2, . . . , and IDn+1 is recurrentlyplaced over the whole of the lead-in area containing the LPP-addedpre-recorded area.

FIG. 12 shows an information-signal recording and reproducing apparatuswhich operates on an optical disc 22 such as a DVD-RW or a DVD-R. Theapparatus of FIG. 12 records and reproduces information (a signal) onand from the optical disc 22 while scanning the optical disc 22 by alaser beam at a constant linear velocity selectable from the normallinear velocity and at least one higher linear velocity equal to aninteger multiple of the normal linear velocity. The apparatus of FIG. 12includes a key input unit 10, a system controller 12, a signal processor14, a servo processor 16, a driver 18, a spindle motor 20, an opticalhead (optical pickup) 24, an amplifier unit 26, a memory 28, anaudio-video encoding and decoding unit 30, a memory 32, an input/outputterminal 34, and a temperature sensor 36.

The temperature sensor 36 is located near the optical disc 22 placed inposition within the apparatus. The temperature sensor 36 detects anambient temperature of the optical disc 22. The temperature sensor 36 isconnected to the amplifier unit 26.

The spindle motor 20 acts to rotate the optical disc 22. While thespindle motor 20 rotates the optical disc 22, the optical head 24 writesand reads information (a signal) thereon and therefrom. The spindlemotor 20 is driven and controlled by the driver 18. The spindle motor 20is provided with an FG generator and a rotational position sensor (anangular position sensor). The rotational position sensor includes, forexample, a Hall element. The FG generator outputs an FG signal (arotational speed signal). The Hall element outputs a rotational positionsignal. The FG signal and the rotational position signal are fed back tothe driver 18.

The optical head 24 faces the optical disc 22 placed in position withinthe apparatus. A feed motor (not shown) moves the optical head 24radially with respect to the optical disc 22. The feed motor is drivenby the driver 18. The optical head 24 includes a semiconductor laser, acollimator lens, and an objective lens. The semiconductor laser acts asa source for emitting a light beam (a laser beam). The emitted laserbeam is focused into a laser spot on the optical disc 22 by thecollimator lens and the objective lens. The optical head 24 includes a2-axis actuator for moving the objective lens to implement focusing andtracking of the laser spot with respect to a track on the optical disc22. The semiconductor laser is driven by a laser drive circuit in theamplifier unit 26. The 2-axis actuator is driven by the driver 18.

The key input unit 10 includes a plurality of keys which can be operatedby a user. The key input unit 10 generates command signals in accordancewith its operation by the user. The command signals are transmitted fromthe key input unit 10 to the system controller 12. The command signalsinclude a command signal for starting a recording mode of operation ofthe apparatus, and a command signal for starting a playback mode ofoperation of the apparatus. The key input unit 10 generates control datain accordance with its operation by the user. The control data are sentfrom the key input unit 10 to the system controller 12.

The system controller 12 includes, for example, a microcomputer or asimilar device which operates in accordance with a control programstored in its internal memory. The control program is designed to enablethe system controller 12 to implement operation steps mentioned later.The system controller 12 controls the signal processor 14, the servoprocessor 16, the amplifier unit 26, and the audio-video encoding anddecoding unit 30 in response to the command signals fed from the keyinput unit 10.

Control data can be fed to the system controller 12 via an inputterminal (not shown). The control data fed to the system controller 12via the input terminal, and the control data fed to the systemcontroller 12 from the key input unit 10 include a signal for adjustingthe resolution of pictures represented by contents information to berecorded, a signal for separating quickly-moving scenes such as carracing scenes represented by contents information, and a signal forgiving priority to a recording time. The system controller 12 changes anactual recording time in accordance with the control data. The systemcontroller 12 enables the setting of the actual recording time to beselected by the user.

When the apparatus is required to start operating in the playback mode,the key input unit 10 is actuated to generate the playback start commandsignal. The playback start command signal is sent from the key inputunit 10 to the system controller 12. The system controller 12 controlsthe servo processor 16 and the amplifier unit 26 in response to theplayback start command signal, thereby starting the playback mode ofoperation of the apparatus. The control of the servo processor 16includes steps of controlling the driver 18. Firstly, the systemcontroller 12 starts rotation of the optical disc 22 and application ofa laser spot thereon through the control of the driver 18. The opticalhead 24 is controlled by the driver 18, thereby reading out addressinformation (LPP address information) from the optical disc 22. Thereadout address information is transmitted from the optical head 24 tothe system controller 12 via the amplifier unit 26. The systemcontroller 12 finds or decides a target sector (a target track portion)to be played back by referring to the address information. The systemcontroller 12 controls the optical head 24 via the servo processor 16,the driver 18, and the feed motor, thereby moving the optical head 24radially with respect to the optical disc 22 and hence moving the laserspot to the target sector on the optical disc 22. When the movement ofthe laser spot to the target sector is completed, the system controller12 operates to start the reproduction of a signal from the target sectoron the optical disc 22. In this way, the playback mode of operation ofthe apparatus is started. During the playback mode of operation of theapparatus, the target sector is repetitively changed from one toanother.

During the playback mode of operation of the apparatus, the optical head24 scans the optical disc 22 and generates a reproduced RF signalcontaining information read out therefrom. The optical head 24 outputsthe RF signal to the amplifier unit 26. The amplifier unit 26 enlargesthe RF signal from the optical head 24. The amplifier unit 26 generatesa main reproduced signal from the enlarged RF signal. In addition, theamplifier unit 26 generates a servo error signal (tracking and focusingservo error signals) from the output signal of the optical head 24. Theamplifier unit 26 includes an equalizer for optimizing the frequencyaspect of the main reproduced signal. Also, the amplifier unit 26includes a PLL (phase locked loop) circuit for extracting a bit clocksignal from the equalized main reproduced signal, and for generating aspeed servo signal from the equalized main reproduced signal.Furthermore, the amplifier unit 26 includes a jitter generator forcomparing the time bases of the bit clock signal and the equalized mainreproduced signal, and for detecting jitter components from the resultsof the time-base comparison. A signal of the detected jitter componentsis sent from the amplifier unit 26 to the system controller 12. Thetracking and focusing servo signals and the speed servo signal are sentfrom the amplifier unit 26 to the servo processor 16. The equalized mainreproduced signal is transmitted from the amplifier unit 26 to thesignal processor 14.

The servo processor 16 receives the speed servo signal and the trackingand focusing servo signals from the amplifier unit 26. The servoprocessor 16 receives the rotation servo signals from the spindle motor20 via the driver 18. In response to these servo signals, the servoprocessor 16 implements corresponding servo control procedures.

Specifically, the servo processor 16 generates a rotation control signalon the basis of the speed servo signal and the rotation servo signals.The rotation control signal is sent from the servo processor 16 to thespindle motor 20 via the driver 18. The spindle motor 20 rotates at aspeed depending on the rotation control signal. The rotation controlsignal is designed to rotate the optical disc 22 at a speedcorresponding to a selected constant linear velocity or a given constantlinear velocity relating to the scanning of the optical disc 22.

In addition, the servo processor 16 generates servo control signals onthe basis of the focusing and tracking servo signals. The servo controlsignals are sent from the servo processor 16 to the 2-axis actuator inthe optical head 22 via the driver 18. The 2-axis actuator controls thelaser spot on the optical disc 22 in response to the servo controlsignals, and thereby implements focusing and tracking of the laser spotwith respect to a track on the optical disc 22.

During the playback mode of operation of the apparatus, the signalprocessor 14 receives the main reproduced signal from the amplifier unit26. The signal processor 14 is controlled by the system controller 12,thereby converting the main reproduced signal into a correspondingreproduced digital signal. The signal processor 14 detects a sync signalfrom the reproduced digital signal. The signal processor 14 decodes an8-16 modulation-resultant signal of the reproduced digital signal intoNRZ data, that is, non-return-to-zero data. The signal processor 14subjects the NRZ data to error correction for every correction block(every ECC block), thereby generating a sector address signal and firstand second information signals. The sector address signal represents theaddress of a currently-accessed sector on the optical disc 22. The syncsignal and the sector address signal are fed from the signal processor14 to the system controller 12.

During the playback mode of operation of the apparatus, the signalprocessor 14 temporarily stores the first and second information signalsin the memory 28. Thus, the signal processor 14 writes the first andsecond information signals into the memory 28, and reads the first andsecond information signals therefrom. Writing and reading the first andsecond information signals into and from the memory 28 are controlled toabsorb a time-domain change in the transfer rates of the first andsecond information signals. The memory 28 includes, for example, a D-RAMhaving a capacity of 4 Mbytes or 64 Mbytes. The signal processor 14outputs the readout signal (the first and second information signalsread out from the memory 28) to the audio-video encoding and decodingunit 30.

In the case where the first and second information signals fed from thememory 28 via the signal processor 14 are compressed data (for example,MPEG2 data) in which audio data and video data are multiplexed, theaudio-video encoding and decoding unit 30 separates the first and secondinformation signals into compressed audio data and compressed videodata. The audio-video encoding and decoding unit 30 expands and decodesthe compressed audio data into non-compressed audio data. In addition,the audio-vide encoding and decoding unit 30 expands and decodes thecompressed video data into non-compressed video data. During theexpansively decoding process, the audio-video encoding and decoding unit30 temporarily stores signals and data in the memory 32. The memory 32includes, for example, a D-RAM having a capacity of 4 Mbytes or 64Mbytes. The audio-video encoding and decoding unit 30 converts thenon-compressed audio data into a corresponding analog audio signalthrough digital-to-analog conversion. Also, the audio-video encoding anddecoding unit 30 converts the non-compressed video data into acorresponding analog video signal through digital-to-analog conversion.The audio-video encoding and decoding unit 30 applies the analog audiosignal and the analog video signal to the input/output terminal 34. Theanalog audio signal and the analog video signal are transmitted to anexternal via the input/output terminal 34.

When the apparatus is required to start operating in the recording mode,the key input unit 10 is actuated to generate the recording startcommand signal. The recording start command signal is transmitted fromthe key input unit 10 to the system controller 12. The system controller12 controls the servo processor 16 and the amplifier unit 26 in responseto the recording start command signal, thereby starting the recordingmode of operation of the apparatus. The control of the servo processor16 includes steps of controlling the driver 18. Firstly, the systemcontroller 12 starts rotation of the optical disc 22 and application ofa laser spot thereon through the control of the driver 18. The opticalhead 24 is controlled by the driver 18, thereby reading out addressinformation (LPP address information) from the optical disc 22. Thereadout address information is sent from the optical head 24 to thesystem controller 12 via the amplifier unit 26. The system controller 12finds or decides a target sector (a target track portion), on which asignal is to be recorded, by referring to the address information. Thesystem controller 12 controls the optical head 24 via the servoprocessor 16 and the driver 18, thereby moving the laser spot to thetarget sector on the optical disc 22. During the recording mode ofoperation of the apparatus, the target sector is repetitively changedfrom one to another.

During the recording mode of operation of the apparatus, an audio signaland a video signal to be recorded are fed via the input/output terminal34 to the audio-video encoding and decoding unit 30. The audio-videoencoding and decoding unit 30 converts the audio signal intocorresponding audio data through analog-to-digital conversion. Inaddition, the audio-video encoding and decoding unit 30 converts thevideo signal into corresponding video data through analog-to-digitalconversion. The audio-video encoding and decoding unit 30 compressivelyencodes the audio data and the video data into compressed audio data andcompressed video data (for example, MPEG2 audio data and MPEG2 videodata). The audio-video encoding and decoding unit 30 multiplexes thecompressed audio data and the compressed video data to form multiplexedcontents data. The audio-vide encoding and decoding unit 30 outputs themultiplexed contents data to the signal processor 14. During thecompressively encoding process, the audio-video encoding and decodingunit 30 temporarily stores data in the memory 32.

During the recording mode of operation of the apparatus, the signalprocessor 14 adds error correction code signals (ECC signals or PI andPO signals) to the multiplexed contents data. The signal processor 12subjects the ECC-added data to NRZ and 8-16 modulation encodingprocedures. The signal processor 14 adds a sync signal to theencoding-resultant contents data to form sync-added contents data. Thesync signal is fed from the system controller 12. The sync-addedcontents data are temporarily stored in the memory 28. The sync-addedcontents data are read out from the memory 28 at a data ratecorresponding to a data rate of the signal recording on the optical disc22. The signal processor 14 subjects the readout contents data to givenmodulation for record. The signal processor 14 outputs themodulation-resultant signal to the amplifier unit 26. The output signalof the signal processor 14 is an 8-16 modulation-resultant signal. Theamplifier unit 26 corrects the waveform of the output signal of thesignal processor 14. The amplifier unit 26 generates a laser drivesignal in response to the waveform-correction-resultant signal. Theamplifier unit 26 outputs the laser drive signal to the optical head 24.The optical head 24 records the output signal of the amplifier unit 26on the target sector (the target track portion) on the optical disc 22.

As shown in FIG. 13, the amplifier unit 26 includes a servo error signalgeneration circuit 49, an RF amplifier 50, an equalizer 52, a PLLcircuit 54, a jitter signal generation circuit 56, a laser drive circuit58, a waveform correction circuit 60, a switch 62, a test patterngeneration circuit 64, a temperature detection circuit 66, an asymmetrydetection circuit 70, a PLL circuit 71, a wobble detection circuit 72,an address detection circuit 73, and a timing signal generation circuit74.

The temperature detection circuit 66 in the amplifier unit 26 isconnected to the temperature sensor 36 and the system controller 12 (seeFIG. 12). The temperature detection circuit 66 is an interface betweenthe temperature sensor 36 and the system controller 12. A signalrepresentative of the ambient temperature of the optical disc 22 istransmitted from the temperature sensor 36 to the system controller 12via the temperature detection circuit 66.

The amplifier unit 26 operates as follows. The servo error signalgeneration circuit 49 and the RF amplifier 50 in the amplifier unit 26receive the output signal of the optical head 24. The servo error signalgeneration circuit 49 produces a servo error signal from the outputsignal of the optical head 24. The servo error signal generation circuit49 outputs the servo error signal to the servo processor 16. During theplayback mode of operation of the apparatus, the RF amplifier 50enlarges the output signal of the optical head 24. The RF amplifier 50outputs the enlarged signal to the equalizer 52 and the asymmetrydetection circuit 70. The equalizer 52 optimizes the frequency aspect ofthe enlarged signal. The equalizer 52 outputs the resultant signal tothe PLL circuit 54. The PLL circuit 54 subjects the output signal of theequalizer 52 to PLL control, thereby generating reproduced data (readdata), a bit clock signal, and a speed servo signal (a signalrepresenting the rotational speed of the optical disc 22). The PLLcircuit 54 outputs the reproduced data (the read data) to the jittersignal generation circuit 56 and the signal processor 14. The PLLcircuit 54 outputs the bit clock signal to the jitter signal generationcircuit 56. The PLL circuit 54 outputs the speed servo signal to theservo processor 16. The jitter signal generation circuit 56 compares thetime bases of the reproduced data and the bit clock signal, therebydetecting jitter components and generating a signal of the detectedjitter components. The jitter signal generation circuit 56 outputs thesignal of the jitter components to the system controller 12. The timingof the jitter detection by the jitter signal generation circuit 56 iscontrolled by the timing signal generation circuit 74.

The output signal of the RF amplifier 50 contains a reproduced 8-16modulation-resultant signal during the playback mode of operation of theapparatus. The asymmetry detection circuit 70 decides, from the outputsignal of the RF amplifier 50, the position of the center of ashortest-period signal “3T” relative to the peak and bottom amplitudepositions of a longest-period signal “11T” of the reproduced 8-16modulation-resultant signal. The asymmetry detection circuit 70 informsthe system controller 12 of the decision result as a detected asymmetryvalue. The decision by the asymmetry detection circuit 70 corresponds tothe detection of an asymmetry. The timing of the asymmetry detection bythe asymmetry detection circuit 70 is controlled by the timing signalgeneration circuit 74. The wobble detection circuit 72 generates awobble signal (a frequency signal) from an output signal of the servoerror signal generation circuit 49. When the optical disc 22 is scannedat the normal linear velocity (3.49 m/s), the wobble signal has afrequency of about 140 kHz. The wobble detection circuit 72 outputs thewobble signal to the PLL circuit 71 as a signal frequency-multiplied bya recording clock signal having a frequency of about 26.16 MHz. The PLLcircuit 71 generates a spindle speed signal and a recording clock signalin response to the wobble signal. The PLL circuit 71 outputs the spindlespeed signal and the recording clock signal to the timing signalgeneration circuit 74 and the system controller 12. The addressgeneration circuit 73 produces a signal of an LPP address on the opticaldisc 22 from the output signal of the servo error signal generationcircuit 49. The address generation circuit 73 outputs the LPP addresssignal to the timing signal generation circuit 74, the system controller12, and the signal processor 14. The timing signal generation circuit 74produces a recording/reproduction timing signal in response to theoutput signals from the PLL circuit 71 and the address detection circuit73. As previously mentioned, the recording and reproduction ofinformation on and from one ECC block is synchronous with the LPPaddress signal. The timing signal generation circuit 74 counts pulses inthe recording clock signal (or a reproducing clock signal) from everyreference moment determined by the LPP address signal, and decides arecording/reproduction timing on the basis of the counted pulse numberwhich corresponds to a sector to be accessed in an ECC block. The timingsignal generation circuit 74 outputs the recording/reproduction timingsignal to the system controller 12 and the signal processor 14.Similarly, the timing signal generation circuit 74 produces areproduction timing signal in response to the output signals from thePLL circuit 71 and the address detection circuit 73. The timing signalgeneration circuit 74 outputs the reproduction timing signal to thejitter signal generation circuit 56 and the asymmetry detection circuit70, thereby controlling the timing of the jitter detection by the jittersignal generation circuit 56 and the timing of the asymmetry detectionby the asymmetry detection circuit 70.

The laser drive circuit 58 in the amplifier unit 26 generates a laserdrive signal. The laser drive circuit 58 outputs the laser drive signalto the semiconductor laser within the optical head 24. The semiconductorlaser emits the laser beam in response to the laser drive signal. Theoptical head 24 includes a photodiode exposed to a portion of the laserbeam emitted by the semiconductor laser. The photodiode monitors thelaser beam. The photodiode is also referred to as the monitor diode. Thephotodiode generates a signal representing the intensity (or the power)of the laser beam. The photodiode feeds the laser intensity signal backto the laser drive circuit 58 in the amplifier unit 26. The laser drivecircuit 58 controls the laser drive signal in response to the laserintensity signal. The semiconductor laser, the photodiode, and the laserdrive circuit 58 compose an APC (automatic power control) circuit forregulating the power of the laser beam at a desired level controlled bythe system controller 12. The APC can be selectively enabled anddisabled by the system controller 12. For example, the APC is enabledduring the playback mode of operation of the apparatus, and is disabledduring the recording mode of operation of the apparatus. The laser drivecircuit 58 transmits the laser intensity signal to an A/D converterwithin the system controller 12. Thus, the intensity of the laser beamcan be monitored by the system controller 12.

During the recording mode of operation of the apparatus, the timingsignal generation circuit 74 produces a timing signal corresponding to asector to be accessed. The timing signal generation circuit 74 outputsthe timing signal to the test pattern generation circuit 64, the systemcontroller 12, and the signal processor 14. The test pattern generationcircuit 64 produces a signal of a test pattern in response to the outputsignal from the timing signal generation circuit 74 while beingcontrolled by the system controller 12. The test pattern generationcircuit 64 outputs the test pattern signal to the switch 62. The switch62 receives the 8-16 modulation-resultant signal (the write data or thecontents data to be recorded) from the signal processor 14. The switch62 is controlled by the system controller 12, selecting one of the testpattern signal and the 8-16 modulation-resultant signal and outputtingthe selected signal to the waveform correction circuit 60.

The waveform correction circuit 60 converts the waveform of the outputsignal of the switch 62 into a recording waveform equivalent to thatshown in FIG. 1. The waveform correction circuit 60 can set waveformcorrection parameters which determine the recording power level Po, theerasing power level Pe, and the pulse widths Ttop, Tmp, and Tcl (seeFIG. 1). The waveform correction parameters may also determine the biaspower level Pb (see FIG. 1). The waveform correction parameters set bythe waveform correction circuit 60 can be changed by the systemcontroller 12. Preferably, change of the waveform correction parametersis accorded with change of the linear velocity relating to the scanningof the optical disc 22. The waveform correction circuit 60 outputs thewaveform-correction-resultant signal to the laser drive circuit 58.

The waveform correction circuit 60 and the switch 62 are controlled bythe system controller 12 to provide a time base change in a great unitin accordance with change of the linear velocity relating to thescanning of the optical disc 22. The waveform correction parameterswhich determine the laser power levels Po, Pe, and Pb, and the pulsewidths Ttop, Tmp, and Tcl (see FIG. 1) may be set by the waveformcorrection circuit 60 so as to optimize the asymmetry value (or theasymmetry value and the jitter value).

The test pattern signal generated by the test pattern generation circuit64 has the alternation of the lowest-frequency signal (thelongest-period signal) “11T” and the highest-frequency signal (theshortest-period signal) “3T” of the 8-16 modulation-resultant signal.Preferably, the test pattern signal is selected by the switch 62 for atime interval corresponding to one ECC block. Test data originating fromthe test pattern signal are recorded on an ECC block. The ECC block iscomposed of 16 successive sectors. The ECC block loaded with the testdata is also referred to as the test ECC block. The lowest-frequencysignal “11T” is recorded on the first sector in the test ECC block. Thehighest-frequency signal “3T” is recorded on the second sector in thetest ECC block. Similarly, the lowest-frequency signal “11T” and thehighest-frequency signal “3T” are alternately recorded on the third andlater sectors in the test ECC block. Thus, eight pairs of thelowest-frequency signal “11T” and the highest-frequency signal “3T” areassigned to eight pairs of two successive sectors, respectively. Duringthe recording of the test data, the system controller 12 changes atleast one of the waveform correction parameters set by the waveformcorrection circuit 60 among eight different statuses assigned to theeight pairs of the lowest-frequency signal “11T” and thehighest-frequency signal “3T” respectively.

During the playback mode of operation of the apparatus, the systemcontroller 12 detects an access to the test ECC block. The timing signalgeneration circuit 74 produces timing pulses corresponding to the frontends of the sectors in the test ECC block respectively. The asymmetrydetection circuit 70 samples and holds the output signal of the RFamplifier 50 in response to the timing pulses fed from the timing signalgeneration circuit 74. Specifically, the asymmetry detection circuit 70samples and holds a peak and a bottom of the lowest-frequency signal“11T” reproduced from the first sector in the test ECC block. Theasymmetry detection circuit 70 samples and holds a center level of thehighest-frequency signal “3T” reproduced from the second sector in thetest ECC block. Similarly, the asymmetry detection circuit 70 samplesand holds peaks and bottoms of the lowest-frequency signals “11T” andcenter levels of the highest-frequency signals “3T” reproduced from thelater sectors in the test ECC block. Thus, a peak and a bottom of thelowest-frequency signal “11T”, and a center level of thehighest-frequency signal “3T” are detected for each of the eightdifferent-status pairs of the lowest-frequency signal “11T” and thehighest-frequency signal “3T”. The asymmetry detection circuit 70converts the sample-and-hold results into digital data representing thedetected asymmetries for the respective eight different-status pairs ofthe lowest-frequency signal “11T” and the highest-frequency signal “3T”.The asymmetry detection circuit 70 outputs the asymmetry data to thesystem controller 12.

The system controller 12 processes the asymmetry data. Specifically, thesystem controller 12 decides best one among the detected asymmetries,and detects one among the eight different-status pairs of thelowest-frequency signal “11T” and the highest-frequency signal “3T”which corresponds to the decided best asymmetry. During a laterrecording mode of operation of the apparatus, the system controller 12enables the waveform correction circuit 60 to set the waveformcorrection parameters in accordance with the best-asymmetry pair of thelowest-frequency signal “11T” and the highest-frequency signal “3T”.

Operation of the apparatus will be further explained. When an opticaldisc 22 is placed in the apparatus, the optical head 24 is controlled toscan the optical disc 22 at the normal linear velocity and to reproduceinformation pieces from at least one complete set of fields ID1, ID2, .. . , and IDn+1 on the lead-in area of the optical disc 22. Thereproduced information pieces are transmitted from the optical head 24to the system controller 12 via the amplifier unit 26 and the signalprocessor 14. The system controller 12 decides a first total number ofthe fields ID1, ID2, . . . , and IDn+1 in response to the reproducedinformation pieces. The system controller 12 recovers an extension codefrom the reproduced information piece corresponding to the field ID1.The system controller 12 decides a second total number of the fieldsID1, ID2, . . . , and IDn+1 in accordance with the recovered extensioncode. The system controller 12 confirms whether the first total numberand the second total number are equal to each other. In the case whereit is confirmed that the first total number and the second total numberare equal to each other, the system controller 12 derives a recommendedrecording power level Po, a recommended erasing power level Pe, arecommended bias power level Pb, recommended pulse widths Ttop, Tmp, andTcl, and a desired disc scanning velocity value (mX) from theinformation pieces corresponding to specified later fields among thefields ID1, ID2, . . . , and IDn+1. The specified later fields are thefields ID2 and ID5 when “n+1” is equal to “5”. The specified laterfields are the fields ID6 and ID7 when “n+1” is equal to “7”. Thespecified later fields are the fields IDn and IDn+1 when “n+1” isgreater than “7”. For example, in the case where the optical disc 22 isdesigned to be scanned at a linear velocity selectable from the normallinear velocity, the 2-fold linear velocity, and the 4-fold linearvelocity, the specified later fields are the fields ID8 and ID9 whichare assigned to the 4-fold linear velocity. During a later recordingmode of operation of the apparatus, the system controller 12 enables thewaveform correction circuit 60 to set the waveform correction parametersto equalize an actual recording power level Po, an actual erasing powerlevel Pe, an actual bias power level Pb, and actual pulse widths Ttop,Tmp, and Tcl to the recommended ones. In addition, the system controller12 controls the spindle motor 20 via the servo processor 16 and thedriver 18 so that the optical disc 22 will be scanned at a linearvelocity equal to the desired disc scanning velocity value (mX).

FIG. 14 shows an example of the internal structure of the waveformcorrection circuit 60. The waveform correction circuit 60 of FIG. 14includes a variable delay device 60A, a signal generator 60B, a summingdevice 60C, a variable delay device 60D, a signal generator 60E, a delaydevice 60F, an AND gate 60G, a pulse generator 60H, and a signalgenerator 60J.

The variable delay device 60A receives the output signal of the switch62 (see FIG. 13). The variable delay device 60A defers the receivedsignal by a time interval which corresponds to the pulse width Tcl (seeFIG. 1), and which can be adjusted by the system controller 12 (see FIG.12). The variable delay device 60A outputs the deferred signal to thesignal generator 60B. In response to every falling edge in the outputsignal of the variable delay device 60A, the signal generator 60Bproduces a signal having a level which corresponds to the erasing powerlevel Pe (see FIG. 1) minus the bias power level Pb (see FIG. 1), andwhich can be adjusted by the system controller 12. The signal generator60B outputs the signal of the erasing power level Pe minus the biaspower level Pb to the summing device 60C.

The variable delay device 60D receives the output signal of the switch62. The variable delay device 60D defers the received signal by a timeinterval which corresponds to a 2T interval minus the pulse width Ttop(see FIG. 1), and which can be adjusted by the system controller 12. Thevariable delay device 60D outputs the deferred signal to the signalgenerators 60B and 60E. In response to every rising edge in the outputsignal of the variable delay device 60D, the signal generator 60Bterminates the production of the signal of the erasing power level Peminus the bias power level Pb. In response to every rising edge in theoutput signal of the variable delay device 60D, the signal generator 60Eproduces a signal having a level which corresponds to the recordingpower level Po (see FIG. 1) minus the bias power level Pb, and which canbe adjusted by the system controller 12. The signal generator 60Eoutputs the signal of the recording power level Po minus the bias powerlevel Pb to the summing device 60C. The signal generator 60E responds toa clock signal related to the output signal of the switch 62.Specifically, the signal generator 60E terminates the production of thesignal of the recording power level Po minus the bias power level Pb atthe end of a 1T interval provided by the clock signal.

The delay device 60F receives the output signal of the switch 62. Thedelay device 60F defers the received signal by a 2T interval in responseto the clock signal. The delay device 60F outputs the deferred signal toa first input terminal of the AND gate 60G. A second input terminal ofthe AND gate 60G receives the output signal of the switch 62. The ANDgate 60G executes AND operation between the output signals of the delaydevice 60F and the switch 62. The AND gate 60G outputs the resultantsignal to the pulse generator 60H. Only when the output signal of theAND gate 60G is in its high level state, the pulse generator 60Hproduces a pulse signal (a pulse train signal). The pulse generator 60Hresponds to the clock signal so that the pulse signal produced by thepulse generator 60H will have one pulse per 1T interval, and that everyfalling edge in the pulse signal will coincide with the end of a 1Tinterval. The amplitude of the pulse signal corresponds to the recordingpower level Po minus the bias power level Pb, and can be adjusted by thesystem controller 12. The pulse width or the duty cycle of the pulsesignal corresponds to the pulse width Tmp (see FIG. 1), and can beadjusted by the system controller 12. The pulse generator 60H outputsthe pulse signal to the summing device 60C.

The signal generator 60J produces a signal having a level whichcorresponds to the bias power level Pb, and which can be adjusted by thesystem controller 12. The signal generator 60J outputs the signal of thebias power level Pb to the summing device 60C. The summing device 60Cadds the output signals of the devices 60B, 60E, 60H, and 60J togenerate a waveform-correction-resultant signal. The summing device 60Coutputs the waveform-correction-resultant signal to the laser drivecircuit 58 (see FIG. 13).

Second Embodiment

A second embodiment of this invention is similar to the first embodimentthereof except for design changes mentioned hereafter.

FIG. 15 shows an optical disc in the second embodiment of thisinvention. The optical disc in FIG. 15 includes an RMD (recordingmanagement data) area and a PC (power calibration) area. The RMD areaextends inward of a disc lead-in area. The PC area extends inward of theRMD area.

An information-signal recording and reproducing apparatus in the secondembodiment of this invention operates as follows. As in the firstembodiment of this invention, the apparatus reproduces informationpieces from at least one complete set of fields ID1, ID2, . . . , andIDn+1 on the lead-in area of the optical disc. The system controller 12in the apparatus derives a recommended recording power level Po, arecommended erasing power level Pe, a recommended bias power level Pb,recommended pulse widths Ttop, Tmp, and Tcl, and a desired disc scanningvelocity value (mX) from the information pieces corresponding tospecified later fields among the fields ID1, ID2, . . . , and IDn+1. Thesystem controller 12 enables the waveform correction circuit 60 to setthe waveform correction parameters to equalize an actual recording powerlevel Po, an actual erasing power level Pe, an actual bias power levelPb, and actual pulse widths Ttop, Tmp, and Tcl to the recommended ones.Then, the apparatus records the test pattern signal on the PC area orthe data area of the optical disc while the system controller 12 changesat least one of the waveform correction parameters set by the waveformcorrection circuit 60. The apparatus reproduces the test pattern signalfrom the optical disc. The apparatus detects at least one of anasymmetry value, a jitter value, an error rate, and a degree ofmodulation from the reproduced test pattern signal. The apparatusdecides an optimal recording power level Po, an optimal erasing powerlevel Pe, an optimal bias power level Pb, and optimal pulse widths Ttop,Tmp, and Tcl on the basis of at least one of the detected asymmetryvalue, the detected jitter value, the detected error rate, and thedetected degree of modulation. Preferably, the apparatus updates therecommended values Po, Pe, Pb, Ttop, Tmp, and Tcl into the optimalvalues in response to at least one of the detected asymmetry value, thedetected jitter value, the detected error rate, and the detected degreeof modulation. During a later recording mode of operation of theapparatus, the system controller 12 enables the waveform correctioncircuit 60 to set the waveform correction parameters to equalize anactual recording power level Po, an actual erasing power level Pe, anactual bias power level Pb, and actual pulse widths Ttop, Tmp, and Tclto the optimal ones. The system controller 12 generates recordingmanagement information representative of the optimal recording powerlevel Po, the optimal erasing power level Pe, the optimal bias powerlevel Pb, and the optimal pulse widths Ttop, Tmp, and Tcl. The apparatusrecords the generated recording management information on the RMD areaof the optical disc.

The RMD area of the optical disc includes a field “1” having 128 bytes.After the recording of a contents signal on the data area of the opticaldisc, the apparatus records 1) information representative of theconditions of the recording of the contents signal and 2) informationpeculiar to the apparatus on the field “1” of the RMD area. When anoptical disc is placed in the apparatus, the apparatus reproducesrecording condition information and peculiar information from the field“1” of the RMD area. The apparatus decides whether or not the recordingcondition information is valid for the apparatus on the basis of thepeculiar information. In the case where the recording conditioninformation is valid, the apparatus uses the recording conditioninformation for a later recording mode of operation thereof. In thiscase, the recording mode of operation of the apparatus can be quicklystarted.

As shown in FIG. 16, the field “1” of the RMD area of the optical discstores 1) an information piece representative of an apparatusidentification factor such as an apparatus maker name, 2) an informationpiece representative of an apparatus serial number, 3) an informationpiece representative of an apparatus model number, 4) an informationpiece representative of a strategy code “1” depending on a disc scanninglinear velocity and corresponding to actual recording conditions storedin a lead-in-area field, 5) an information piece representative of arecording power level, 6) an information piece representative of theexecution date of the recording of a test pattern signal, 7) aninformation piece representative of a recording calibration position inthe PCA area, 8) an information piece about running OPC (optimum powercontrol) or an information piece representative of results andconditions for optimizing a recording power while implementing thesignal recording, 9) an information piece representative of a strategycode “2” depending on a disc scanning linear velocity and correspondingto actual recording conditions stored in a lead-in-area field, 10) aninformation piece representative of an erasing power level depending ona disc scanning linear velocity and corresponding to actual one storedin a lead-in-area field or an information piece representative of theratio “ε” of the erasing power level to the recording power level, 11)an information piece being 8-bit coded data of the recording powerlevel, 12) an information piece representative of an asymmetry value ora “β” value for deciding an optimal power at the time of recording, and13) an information piece representative of an actually-used discscanning linear velocity.

It should be noted that one or more of the information pieces may beomitted from the field “1” of the RMD area of the optical disc.

As previously mentioned, the information piece representative of theactually-used disc scanning linear velocity is recorded on the field “1”of the RMD area of the optical disc. Also, the information piecesrepresentative of the recording power level, the erasing power level,and the strategy values depending on the disc scanning linear velocityare recorded on the field “1” of the RMD area of the optical disc.Furthermore, the information pieces peculiar to the apparatus arerecorded on the field “1” of the RMD area of the optical disc.Accordingly, it is possible to accurately decide whether or not therecording power level, the erasing power level, and the strategy valuesare valid for a next recording mode of operation of the apparatus at adesignated disc scanning linear velocity.

An optical disc designed to be scanned at a linear velocity selectablefrom the normal linear velocity, the 2-fold linear velocity, and the4-fold linear velocity is taken as an example. Normally, the signalrecording is implemented while the optical disc is scanned at thehighest linear velocity, that is, the 4-fold linear velocity.Preferably, in the event that environmental conditions, temperatureconditions, a rotation-caused surface bend of the optical disc, and theeccentricity of the optical disc are in predetermined undesirableranges, the signal recording is implemented while the optical disc isscanned at the second highest linear velocity, that is, the 2-foldlinear velocity, to compensate for the undesirableness. In such a case,an information piece representative of the actually-used disc scanninglinear velocity (the 2-fold linear velocity) is recorded on the field“1” of the RMD area of the optical disc. Accordingly, the disc scanninglinear velocity can be used for the next signal recording without makinga mistake.

Information pieces representative of different disc scanning linearvelocities may be recorded on different portions of the RMD area of theoptical disc. In this case, it is possible to identify a disc scanninglinear velocity from a portion of the RMD area on which an informationpiece thereof is recorded.

Third Embodiment

A third embodiment of this invention is similar to the first or secondembodiment thereof except for design changes mentioned hereafter.According to the third embodiment of this invention, one lead-in-areaLPP-information field, three lead-in-area LPP-information fields, ormore lead-in-area LPP-information fields are added as a disc scanninglinear velocity is added. Preferably, an information piecerepresentative of a servo system gain depending on a disc scanninglinear velocity, an information piece representative of the degree ofmodulation, and an information piece representative of a jitter valueare recorded as lead-in-area LPP-information fields in addition toinformation pieces of a recording power level, an erasing power level, abias power level, and strategy values.

Fourth Embodiment

A fourth embodiment of this invention is similar to one of the first tothird embodiments thereof except for design changes mentioned hereafter.According to the fourth embodiment of this invention, information piecesof a recording power level, an erasing power level, a bias power level,and strategy values for the normal disc scanning linear velocity arerecorded as lead-in-area LPP-information fields. On the other hand,information pieces of a recording power level, an erasing power level, abias power level, and strategy values for each of the 2-fold or morelinear velocities are previously recorded on an information managementarea of the optical disc which can be subjected to the recording ofnormal information.

The information pieces of the recording power level, the erasing powerlevel, the bias power level, and the strategy values for each of the2-fold or more linear velocities may be recorded as pit information onthe readable emboss area of the optical disc. In the case of awrite-once optical disc such as a DVD-R, these information pieces may berecorded on a pre-write basis.

Fifth Embodiment

A fifth embodiment of this invention is similar to one of the first tofourth embodiments thereof except for design changes mentionedhereafter. The fifth embodiment of this invention is designed to handlean optical disc such as a DVD+RW or a Blu-ray-standard disc. In thefifth embodiment of this invention, the optical disc may be anorganic-pigment DVD-R, a DVD+R, or a Blue-system disc provided that aninformation piece representative of an erasing power level is omitted.

Sixth Embodiment

A sixth embodiment of this invention is similar to one of the first tofifth embodiments thereof except for design changes mentioned hereafter.The sixth embodiment of this invention uses a recording waveform whichdiffers from that of FIG. 1 in at least one of amplitude and timingparameters.

Seventh Embodiment

A seventh embodiment of this invention is similar to one of the first tosixth embodiments thereof except for design changes mentioned hereafter.The seventh embodiment of this invention is designed to handle amagneto-optical disc, an MD, a DWDD, an ASMO, or a MAMMOS.

Advantages Provided by Embodiments

According to the first to seventh embodiments of this invention, it isunnecessary to alter the standards for an optical disc even when ahigher disc scanning linear velocity is added. Furthermore, it ispossible to remove or reduce a waste of recording condition informationstored in an optical disc. The redundancy of the recording conditioninformation stored in the optical disc can be effectively increased, andthe recording area of the optical disc can be efficiently utilized.

Regarding an optical disc, it is possible to detect a highest linearvelocity relating to the scanning of the disc. The signal recording canbe implemented while an optical disc is scanned at an optimal linearvelocity selected from the normal linear velocity and the higher linearvelocities. In the event that environmental conditions, temperatureconditions, a rotation-caused surface bend of an optical disc, and theeccentricity of the optical disc are in predetermined undesirableranges, the signal recording is implemented while the optical disc isscanned at a linear velocity lower than the highest linear velocity tocompensate for the undesirableness.

Recording condition information can easily be read out from an opticaldisc designed to be scanned at a linear velocity selected among thenormal linear velocity and the higher linear velocities. There is nowaste of the recording condition information stored in the optical disc.Accordingly, a desired portion of the recording condition informationcan be obtained in a short time. Since the redundancy of the recordingcondition information stored in the optical disc is relatively high, therecording condition information can be reliably retrieved.

1. A laser-beam-scanned optical disc including an information recordingarea and an information management area, wherein units of signalrecording and signal reproduction on and from at least one of theinformation recording area and the information management area areblocks including first blocks each duplicately having a block addressand second blocks each having both a block address and a managementinformation piece, the information recording area storing blocks amongthe first blocks, the information management area storing the secondblocks having recording management information including portionscorresponding to respective at least three different integer multiplesof a normal velocity relating to scanning of the disc, wherein each ofthe portions of the recording management information contains a firstinformation piece representative of a recording strategy being atime-domain recording laser waveform for recording of information on theinformation recording area and a second information piece representativeof a recording laser power for recording of information on theinformation recording area.
 2. A laser-beam-scanned optical disc asrecited in claim 1, comprising a DVD.
 3. A laser-beam-scanned opticaldisc as recited in claim 1, comprising one of a DVD-R and a DVD-RW.
 4. Alaser-beam-scanned optical disc as recited in claim 1, comprising one ofa DVD+R and a DVD+RW.
 5. A laser-beam-scanned optical disc as recited inclaim 1, comprising a Blue-system disc.
 6. An apparatus for recordingand reproducing information on and from a laser-beam-scanned opticaldisc including an information recording area and an informationmanagement area, wherein units of signal recording and signalreproduction on and from at least one of the information recording areaand the information management area are blocks including first blockseach duplicately having a block address and second blocks each havingboth a block address and a management information piece, the informationrecording area storing blocks among the first blocks, the informationmanagement area storing the second blocks having recording managementinformation including portions corresponding to respective at leastthree different integer multiples of a normal velocity relating toscanning of the disc, wherein each of the portions of the recordingmanagement information contains a first information piece representativeof a recording strategy being a time-domain recording laser waveform forrecording of information on the information recording area and a secondinformation piece representative of a recording laser power forrecording of information on the information recording area, theapparatus comprising: first means for reading, from the informationmanagement area of the disc, one of the portions of the recordingmanagement information which corresponds to desired one of the at leastthree different integer multiples of the normal velocity; second meansfor setting an actual recording strategy and an actual recording powerof a laser beam in accordance with the recording strategy and therecording laser power represented by the portion of the recordingmanagement information which is read by the first means; and third meansfor recording information on the information recording area of the discby use of the laser beam having the actual recording strategy and theactual recording power set by the second means.
 7. An apparatus asrecited in claim 6, wherein the disc comprises a DVD.
 8. An apparatus asrecited in claim 6, wherein the disc comprises one of a DVD-R and aDVD-RW.
 9. An apparatus as recited in claim 6, wherein the disccomprises one of a DVD+R and a DVD+RW.
 10. An apparatus as recited inclaim 6, wherein the disc comprises a Blue-system disc.
 11. A method ofrecording and reproducing information on and from a laser-beam-scannedoptical disc including an information recording area and an informationmanagement area, wherein units of signal recording and signalreproduction on and from at least one of the information recording areaand the information management area are blocks including first blockseach duplicately having a block address and second blocks each havingboth a block address and a management information piece, the informationrecording area storing blocks among the first blocks, the informationmanagement area storing the second blocks having recording managementinformation including portions corresponding to respective at leastthree different integer multiples of a normal velocity relating toscanning of the disc, wherein each of the portions of the recordingmanagement information contains a first information piece representativeof a recording strategy being a time-domain recording laser waveform forrecording of information on the information recording area and a secondinformation piece representative of a recording laser power forrecording of information on the information recording area, the methodcomprising the steps of: reading, from the information management areaof the disc, one of the portions of the recording management informationwhich corresponds to desired one of the at least three different integermultiples of the normal velocity; setting an actual recording strategyand an actual recording power of a laser beam in accordance with therecording strategy and the recording laser power represented by theportion of the recording management information which is read; andrecording information on the information recording area of the disc byuse of the laser beam having the actual recording strategy and theactual recording power which are set.
 12. A method as recited in claim11, wherein the disc comprises a DVD.
 13. A method as recited in claim11, wherein the disc comprises one of a DVD-R and a DVD-RW.
 14. A methodas recited in claim 11, wherein the disc comprises one of a DVD+R and aDVD+RW.
 15. A method as recited in claim 11, wherein the disc comprisesa Blue-system disc.